Welcome to the Tower-of-Eightness wiki!

If you use this repository you'll be able to build a Tower of Eightness. A W65C02 computer something like this:

I've had it playing primitive games, music (I'm not going to subject you to my musical talents though), controlling a turtle, printing fractals, calculating and printing tables, transmitting morse code and many other things. I've enjoyed and will continue to enjoy messing with it for some time and will keep you all updated here.

Now, the system is based on a backplane card with a small amount of logic on board. You will need a few of the cards to get up and running.

1. CPU Card (If not using the new 8 slot with CPU backplane V3.1
2. Memory Card
3. Serial Card (The Dual ACIA one is best)
4. The GPIO card is recommended if you want to play like Arduino or use the tape and joystick interface.
5. Recommended but not strictly necessary is the ANSI video card. With this you can even draw primitive graphics.

Optionally, you might want to add other functions, some of which are already added to the repo. These other cards add ANSI text with limited graphics, sound output, Centronics printer support & Tower Peripheral Bus support (later) and two whole ports of GPIO based on the BBC Micro's user port per IO card. There is a work in progress of a video card based around the TMS9929 video display processor, as found in the PAL versions of the MSX.

Build instructions will be added as I get to grips with using the GitHub wiki, but you should pay attention to the file ToE_Mon.asm as the default output device is the ANSI video card. Not everyone will want to start with the ANSI video card and many will want to save and load simple listings over the terminal. One other thing. After making a couple of 65C51 serial cards it became apparent that the W65C51 has a serious hardware bug where the TxE bit is stuck on so if you use that version you'll need to add a delay to make the system wait before writing the next character. This bug and other design choices with the 65x51 ACIA have spurred me to start developing a serial card based around the SCC2691 UART chip from Philips.

An important download is required if you want to make the ANSI video card. You'll need at the very least the HEX file from Grant Searle's website. His current web address is http://searle.wales and he has a good selection of other projects worth checking out too.

The needed backplane

The Joystick and tape interface.